"The Dark Arts are many, varied, ever-changing, and eternal. Fighting them is like fighting a many-headed monster, which, each time a neck is severed, sprouts a head even fiercer and cleverer than before. You are fighting that which is unfixed, mutating, indestructible."

The Dark Arts, also known as Dark Magic, refers to any type of magic that is mainly used to cause harm, control, or even death to the victim. The Dark Arts are not necessarily "evil", just because it's labelled "dark".

The Dark Arts are generally regarded as corrupting to those who use them (which is part of the reason they are considered "dark"). After engaging in them extensively for many years, even Tom Marvolo Riddle's appearance demonstrated his corruption — he lost his former handsomeness, eventually taking on serpentine physical qualities and red eyes[1]. Albus Dumbledore, in particular, suggested that engaging in any of the Dark Arts that involve murder was damaging to the soul; for instance, he told Severus Snape that Draco Malfoy's soul was "not yet so damaged" that he is probably capable of murder, but that if he did go through with murder, his soul would be "ripped apart"[1]. This suggests that using very dark magic, such as the Killing Curse, damages an individual's soul. The dark art of creating a Horcrux involves literally splitting the soul for the unnatural purpose of achieving immortality. Quirinus Quirrell was interested in dark magics, initially by a theoretical view to gain recognition, but his curiosity turned to avarice, and eventually he was completely drawn in and corrupted.

According to Snape, the Dark Arts are pragmatic in nature, where every time a branch is defeated, it only comes back "fiercer and cleverer" than before. It is therefore imperative that one's defences must be as versatile as these foul arts themselves.

Dark creatures also have lasting impacts that are deadly or incredibly harmful to those who come into contact with them. Such as when a basilisk fang pierced the arm of Harry Potter, while in the Chamber of Secrets, he was as sure as dead with the venom running rapidly through his veins, until his wound was healed by phoenix tears. Phoenix tears is a rare substance that is hard to come across. Baslisks also petrify people who merely glance their image, but kill when you look it in the eye. Other Dark creatures include Dementors, they have the ability to suck out a person's soul with their kiss. There is no cure for someone who has had their soul removed, they also can not recover from it, but most spend the rest of their life in a vegetative state reliving their worst memories.

Protection

"You are protected, in short, by your ability to love! The only protection that can possibly work against the lure of power like Voldemort's!"

—Albus Dumbledore explains the best type of protection against the Dark Arts[src]

According to Albus Dumbledore, the only power strong enough to enable a person to resist the temptation of the Dark Arts, and to defeat them, is love. He was perhaps referring to the Sacrificial protection shield which Lily Potter used to protect infant Harry Potter and Harry himself later used to protect the defenders of Hogwarts by willingly taking a Killing Curse from the Dark Lord. However he was not killed by this curse, since it only destroyed the part of Voldemort's soul inside him. He spent a brief time in limbo then returned to the land of the living.

Ethical considerations

While the Dark Arts have a bad reputation, overall, dark magic is not, by definition, "evil" magic. Indeed, dark magic can be used for good as well as evil. Even the Killing Curse can be used for good, as Albus Dumbledore said that it would not harm Severus Snape to kill him (Dumbledore) as he had asked Snape to kill him since he was going to die anyway (and it would ultimately serve to fool Voldemort and lead to his destruction).

At the same time, dark magic is not the only type of magic that can be used with the intent to kill. For example, the Severing Charm can kill if used irresponsibly.

The only exception to this rule is the spell which creates a Horcrux; this is an entirely selfish act — taking a life in order to prolong one's own. This act is so reprehensible that the caster's soul becomes fragmented, allowing the creation of a Horcrux. The soul can only be restored by complete remorse for the murder, or repentance, which is actually painful enough to cause death.

Wandlore

The suitability of a wand to perform dark magic depends, at least partly, on its core; dragon heartstring, phoenix feather, and rougarou hair have a reputation for being suitable for it, while it's hard to perform dark magic with unicorn hair wands.

The Dark Arts and the law

"When a wizard goes over ter the Dark Side, there's nothin' and no one that matters to 'em any more [...]"

Also, in times of war, the Ministry of Magic has been known to permit Aurors to use strong Dark magic against its enemies. When Lord Voldemort was in control of wizarding Britain in late 1997 to mid-1998, every aspect of the Dark Arts was legalised and taught at Hogwarts by Death Eater professor Amycus Carrow. However, Voldemort was controlling the Ministry at this time, so it may not be standard protocol.[3]

In addition, there is a matter of degree. The three Unforgivable Curses are punishable by an automatic life sentence in Azkaban Prison[6] when used on humans, except when permitted in wartime, whereas some types of magic can have more benign uses as well as Dark uses and, thus, are presumably not always illegal.

Known Dark magic

Dark spells

A Dark spell is primarily defined as any spell that consistently affects the object in a negative manner, usually associated with varying levels of discomfort.

Dark spells can be classified into three groups: jinxes, hexes, & curses. These groups form a hierarchy, with jinxes at the base, hexes in-between, and curses at the top. The further one ascends up this hierarchy, the more wicked, the stronger, the longer-lasting and the less reversible the Dark spell's effects appear to be. The Unforgivable Curses are the strongest known Dark spells in existence, as their effects are very powerful and their use requires skill.

This potion is said by Voldemort to be "an old piece of Dark Magic"[6]. Its ingredients include a bone from the father unknowingly given, flesh from the servant willingly given, and blood from an enemy of the one for whom it is intended. It creates a new body for a Dark witch or wizard who has used Horcruxes and lost their original body, as Voldemort did. This new body is a replica of the old one and has its former powers too. It apparently requires that the Dark wizard exist within a rudimentary body that can be placed within the cauldron after all the ingredients are added. If the blood of the enemy contains protections or infections, like a love sacrifice or lycanthrophy, it will also affect or protect the wizard or witch reborn with it.

Potion used in a basin in which the locket Horcrux was hidden. Its consumption caused the drinker to see "terrible things", dehydrate, and experience excruciating burning in one's insides. Because of the 'terrible things', it has an effect similar to the presence of a Dementor.[1]

Books can be bewitched to cause harm to anyone who attempts to read them. Examples include Sonnets of a Sorcerer, which causes the reader to speak in rhymes, and an unnamed book that a person can never stop reading. Tom Riddle's Diary is both a cursed book and a Horcrux.

A severed human hand with a candle placed within it. It provides light only to the holder, and is commonly attributed to thieves and plunderers. It is able to penetrate Peruvian Instant Darkness Powder.

This item turned up in Borgin and Burkes, was apparently purchased by Draco Malfoy, and almost killed Katie Bell. It is cursed very heavily, to the extent that merely touching it causes nearly instant death. It has killed at least nineteen Muggles.

A quill that does not require ink, as it writes with the blood of the person using it. What the user writes will be carved onto the back of his or her hand, and the blood from the words sliced into the hand will be magically syphoned and used as ink on the parchment. It is used as a torture device.

Known practitioners

The following wizards and witches are known to have used Dark Magic. Note that as above, the Dark Arts encompass many different types of spells, including many that seem to be in everyday use by most wizards — this section is limited to those who have used strong dark magic at least once.

Known texts

Behind the scenes

Some spells may not be considered Dark magic in and of themselves, but may be used for Dark purposes. For example, the Taboo curse allows the caster to track anyone who says a certain word or name. This gives the caster a great deal of power over people's speech, and spreads fear. It may thus be considered to have Dark applications, such as when it was used by Death Eaters to track their enemies during the Second Wizarding War[3].

The Dark Arts are similar to magic known as maleficium, which is used in a similar manner.